[coreboot-gerrit] Change in coreboot[master]: soc/intel/jasperlake: Add ISST override support

[Karthik Ramasubramanian (Code Review)]

Karthik Ramasubramanian has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/41429 )

Change subject: soc/intel/jasperlake: Add ISST override support
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Patch Set 1:
> Patch Set 1:
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> (1 comment)

Couple of reasons I added this callback:
1) It happens as part of CPU initialization. It definitely happens before mainboard Silicon initialization(as pointed out by Tim). I have to check if mainboard Chip initialization. If this happens before CPU initialization, then we can update the configuration there.
2) If all mainboard initialization happens only after CPU initialization, then there will be a small window for which ISST will be enabled before getting disabled. I am not sure if there is a side-effect of because of that. Also we have to export configure_isst to mainboard and invoke that again to disable it.

These are the reasons I added the callback.